/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.compression;

import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.SystemPropertyUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

/**
 * Creates a new {@link ZlibEncoder} and a new {@link ZlibDecoder}.
 */
public final class ZlibCodecFactory
{
    private static final InternalLogger logger = InternalLoggerFactory
            .getInstance(ZlibCodecFactory.class);

    private static final int DEFAULT_JDK_WINDOW_SIZE = 15;

    private static final int DEFAULT_JDK_MEM_LEVEL = 8;

    private static final boolean noJdkZlibDecoder;

    private static final boolean noJdkZlibEncoder;

    private static final boolean supportsWindowSizeAndMemLevel;

    static
    {
        noJdkZlibDecoder = SystemPropertyUtil.getBoolean(
                "io.netty.noJdkZlibDecoder",
                PlatformDependent.javaVersion() < 7);
        logger.debug("-Dio.netty.noJdkZlibDecoder: {}", noJdkZlibDecoder);

        noJdkZlibEncoder = SystemPropertyUtil
                .getBoolean("io.netty.noJdkZlibEncoder", false);
        logger.debug("-Dio.netty.noJdkZlibEncoder: {}", noJdkZlibEncoder);

        supportsWindowSizeAndMemLevel = noJdkZlibDecoder
                || PlatformDependent.javaVersion() >= 7;
    }

    /**
     * Returns {@code true} if specify a custom window size and mem level is
     * supported.
     */
    public static boolean isSupportingWindowSizeAndMemLevel()
    {
        return supportsWindowSizeAndMemLevel;
    }

    public static ZlibEncoder newZlibEncoder(int compressionLevel)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder)
        {
            return new JZlibEncoder(compressionLevel);
        }
        else
        {
            return new JdkZlibEncoder(compressionLevel);
        }
    }

    public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder)
        {
            return new JZlibEncoder(wrapper);
        }
        else
        {
            return new JdkZlibEncoder(wrapper);
        }
    }

    public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper,
            int compressionLevel)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder)
        {
            return new JZlibEncoder(wrapper, compressionLevel);
        }
        else
        {
            return new JdkZlibEncoder(wrapper, compressionLevel);
        }
    }

    public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper,
            int compressionLevel, int windowBits, int memLevel)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder
                || windowBits != DEFAULT_JDK_WINDOW_SIZE
                || memLevel != DEFAULT_JDK_MEM_LEVEL)
        {
            return new JZlibEncoder(wrapper, compressionLevel, windowBits,
                    memLevel);
        }
        else
        {
            return new JdkZlibEncoder(wrapper, compressionLevel);
        }
    }

    public static ZlibEncoder newZlibEncoder(byte[] dictionary)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder)
        {
            return new JZlibEncoder(dictionary);
        }
        else
        {
            return new JdkZlibEncoder(dictionary);
        }
    }

    public static ZlibEncoder newZlibEncoder(int compressionLevel,
            byte[] dictionary)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder)
        {
            return new JZlibEncoder(compressionLevel, dictionary);
        }
        else
        {
            return new JdkZlibEncoder(compressionLevel, dictionary);
        }
    }

    public static ZlibEncoder newZlibEncoder(int compressionLevel,
            int windowBits, int memLevel, byte[] dictionary)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibEncoder
                || windowBits != DEFAULT_JDK_WINDOW_SIZE
                || memLevel != DEFAULT_JDK_MEM_LEVEL)
        {
            return new JZlibEncoder(compressionLevel, windowBits, memLevel,
                    dictionary);
        }
        else
        {
            return new JdkZlibEncoder(compressionLevel, dictionary);
        }
    }

    public static ZlibDecoder newZlibDecoder()
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibDecoder)
        {
            return new JZlibDecoder();
        }
        else
        {
            return new JdkZlibDecoder();
        }
    }

    public static ZlibDecoder newZlibDecoder(ZlibWrapper wrapper)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibDecoder)
        {
            return new JZlibDecoder(wrapper);
        }
        else
        {
            return new JdkZlibDecoder(wrapper);
        }
    }

    public static ZlibDecoder newZlibDecoder(byte[] dictionary)
    {
        if (PlatformDependent.javaVersion() < 7 || noJdkZlibDecoder)
        {
            return new JZlibDecoder(dictionary);
        }
        else
        {
            return new JdkZlibDecoder(dictionary);
        }
    }

    private ZlibCodecFactory()
    {
        // Unused
    }
}
